Great video ,,,, I have a question ,,, Is the return suction line 100% vapor at the evaporator outlet ? if so how the oil could return to compressor ? I imagine there should some liquid R134a at the evaporator outlet to lift the oil up from the evaporator (but should be all 100% vapor before reaching the compressor) Thank you
Dear Saeed, Yes, we have 100% vapor at the suction side of the compressor, to prevent the compressor from sucking liquid refrigerant, which can cause liquid lock. We call this superheated gaseous refrigerant. The temperature of this superheated gaseous refrigerant has to have a temperature between 5- to 10 degrees Celsius. If the superheat value is too high, then the oil return comes into danger. This can happen when the refrigerant levels becomes too low. We call this difference in superheat, wet or dry vapor. Wet vapor is carrying oil. Dry vapor not. Therefore it is also very important to use the right type of compressor oil, because only a good quality compressor oil has the right miscibility properties in every state of the refrigerant. (Liquid or gaseous) Denso oil types ND-oil 8: Denso specific PAG, with viscosity 46, for R134a refrigerant. (Not useable for R1234yf refrigerant!) ND-oi 12: Denso specific special PAG, with viscosity 46, for R1234yf refrigerant, but can also be used for R134a refrigerant. ND-oil 11: Denso specific POE oil, especially for Denso electric driven scroll compressors.
